[Snappi] Support for DUT statistics - Interface counters, PFC counters, and Queue counters.

[amitpawar12]

Description of PR

Support to pull the DUT statistics, namely interface counters, PFC counters and Queue counters.

This support will enable users to pull the DUT statistics run-time and capture them in form of dictionary for further processing.

Summary:
Fixes # (issue)
#13843

Type of change

• Bug fix
• Testbed and Framework(new/improvement)
• Test case(new/improvement)

Back port request

• 202012
• 202205
• 202305
• 202311
• 202405

Approach

What is the motivation for this PR?

Currently, there is no one stop-place to fetch the DUT statistics and use them for verification, especially the SNAPPI testcases. There should be some way to pull the DUT statistics ( at least important ones) and use them for verification.

How did you do it?

Clear counters:
Common function to clear interface, PFC and queue counter stats.

Interface counters:
Ability to fetch the interface counters for a given DUT and port. Returns dictionary with keys - Rx and Tx packet count, Rx and Tx failures (Error + drops + ovr), and Rx and Tx throughput in Mbps.

PFC counters:
Ability to fetch the PFC counters for a given DUT and port. Returns dictionary with keys - Rx and Tx PFC for the given DUT, port and priority.

Queue counters:
Ability to fetch the Queue counters for a given DUT and port. Internally calls get_egress_queue_count for all the priorities. Returns dictionary with as key with transmitted packets as counter.

How did you verify/test it?

These functions are called as part of new testcases for PFC-ECN.

    for dut, port in dutport_list:
        f_stats = update_dict(m, f_stats, interface_stats(dut, port))
        f_stats = update_dict(m, f_stats, get_pfc_count(dut, port))
        f_stats = update_dict(m, f_stats, get_queue_count(dut, port))

These are then used to create CSV with raw DUT statistics and then to summarize the test in the end.

Any platform specific information?

Supported testbed topology if it's a new test case?

Documentation

[sdszhang]

@vmittal-msft for viz

[sdszhang]

@kamalsahu0001 @selldinesh

[vmittal-msft]

@amitpawar12 What is the difference between get_egress_queue_count and this one ? we may need to use better name here ?

[amitpawar12]

@vmittal-msft :
The get_egress_queue_count returns the egress queue packets ONLY for a certain priority. The get_queue_count is internally calling get_egres_queue_count and returns the dictionary for all the priorities, for a given interface and DUT.

This function is one-stop-place to fetch packet counts for all the priorities for a given interface and DUT.

[developfast]

Ok let's rename get_queue_count() to get_queue_count_all_prio()

[vmittal-msft]

@amitpawar12 we may plan to add such interface for VoQ stats as well as pfcwd stats so our tests may use them.

[amitpawar12]

@amitpawar12 we may plan to add such interface for VoQ stats as well as pfcwd stats so our tests may use them.

@vmittal-msft : Ideally, voq counters, priority-group counters, and drop counters also needs to be added. But they can be targeted in different PR's. Adding is just a one part, we will need to also enhance the test-cases to incorporate checks with these counters.

[sdszhang]

can we use something like pfc_dict[dut]['tx_pfc'][0]

[amitpawar12]

Thanks for the comment. Nested dictionary will require additional logic to initialize and unpacking them. Needs check for the key errors too.

[sdszhang]

same here. try to use multi level dictionary for easy access instead of customized key.

[amitpawar12]

Thanks for the comment. The flat dictionary was used because at the end of the test, entire dictionary was converted into data-frame. However, I have added the nested dictionaries for get_interface_stats, get_pfc_count and queue count function and then flattening it, for use in data-frame.

[sdszhang]

@rraghav-cisco for review, Thanks.

[sdszhang]

@zhixzhu @vmittal-msft @developfast any further comments? or is it fine to approve the updated change?

[yejianquan]

LGTM

[mssonicbld]

Cherry-pick PR to 202405: #14429